It means a word that refers to multiple things.
For example, the word "tree" refers to one tree, but its plural form "trees" refers to 2 or more trees.
plural form means to add a s at the end.
you ( plural or polite form)
There is no such word. If you mean thankful, there is no plural.
The word marriage is not a plural form; the plural form for the noun is marriages. Or, perhaps you mean monogamy, the opposite of polygamy.
The singular noun is mean, the plural form is means.
It is the plural form of the possessive pronouns: His, her, their.
rose plural form
the (plural) in masculin form
I hope you mean "stylo"; if you do, it's short for stylograph, the plural form of which is stylographs. I assume that the plural form for the shortened form would also be no more than an added S to the word.
The word 'utilidades' is a Spanish noun in the feminine plural form. Although its singular form is translated directly as 'utility' or 'usefulness', in its plural form it is interpreted to mean 'profits'.
The word "if" is a usually a conjunction, which has no plural. However, it can be used as a noun to mean a possibility, with the plural form being ifs (e.g. no ifs, ands, or buts).
If you mean rhinoceros, the plural is rhinoceroses ( although a plural form rhinoceros may be encountered also).
Not sure what you mean by deligance, but the plural form of honesty is honesties.